U.S. patent number 4,569,468 [Application Number 06/651,567] was granted by the patent office on 1986-02-11 for continuous forms feed tractor with multiple cut forms chutes.
This patent grant is currently assigned to International Business Machines Corporation. Invention is credited to Jay H. Neer.
United States Patent |
4,569,468 |
Neer |
February 11, 1986 |
Continuous forms feed tractor with multiple cut forms chutes
Abstract
A continuous forms feed tractor in the form of an elongated
housing mounts for rotation thereon, an endless belt from which
protrude longitudinal spaced aligned pins, projectable within
similarly spaced holes along an edge of a continuous forms record
medium for positively feeding the continuous forms medium about a
rotary platen and between the platen and a print head for
implementing printing on the continuous form. The housing is
provided with a long cut forms chute running the length of the
same, below the endless belt and parallel therewith for feeding
letter size or legal size paper sheets onto and about the platen. A
short cut forms chute extends obliquely through the elongated
housing, at the end facing the platen, inclined downwardly towards
the platen and the long cut forms chute for feeding short cut
forms, such as a punch card onto and about the platen for printing
thereon. Forces are applied on pressure feed rolls to press the cut
forms media against the rotating platen driving them around the
platen, up past the print mechanism. A door pivotally mounted to
the side of the housing for movement between a first, upright
position exposing the endless belt and a second position
sandwiching the form between the door and the top of the elongated
housing, allows access to the short cut forms chute, at the side of
the endless belt, when the door is in raised position.
Inventors: |
Neer; Jay H. (Boca Raton,
FL) |
Assignee: |
International Business Machines
Corporation (Armonk, NY)
|
Family
ID: |
24613360 |
Appl.
No.: |
06/651,567 |
Filed: |
September 18, 1984 |
Current U.S.
Class: |
226/74;
400/616.1 |
Current CPC
Class: |
B41J
11/48 (20130101); B41J 11/30 (20130101) |
Current International
Class: |
B41J
11/26 (20060101); B41J 11/48 (20060101); B41J
11/30 (20060101); G03B 001/30 () |
Field of
Search: |
;226/74,75
;271/34,35,198 ;400/616.1,616.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
IBM Technical Disclosure Bulletin, vol. 23, No. 7B, Dec. 1980 by M.
F. Davis, Jr. et al..
|
Primary Examiner: Christian; Leonard D.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak, and
Seas
Claims
I claim:
1. In a continuous forms feed tractor for feeding a continuous form
record medium, having edge perforations, through a printer, about
the periphery of a rotatable cylindrical platen and in front of a
print head facing the platen for imprinting the record medium, said
continuous forms feed tractor being in juxtaposition to the platen,
and wherein, said tractor comprises: an elongated housing including
top and bottom surfaces, a front end and a rear end, said front end
facing said platen and being spaced slightly therefrom, means
within said elongated housing defining a track, an endless belt
born by said track, a sprocket rotatably mounted in said housing
and engaging said belt for driving said belt, means for rotating
said sprocket, a door pivotally mounted to the side of said housing
for movement between a first generally upright, open position,
exposing said endless belt, and a second, face engaging position
with said continuous forms record medium and said housing, pins
projecting outwardly of the face of said endless belt engaging
corresponding perforations along the edge of the continuous forms
record medium to move said continuous forms record medium, the
improvement comprising:
at least one feed chute within said housing, at least a portion of
said feed chute lying to the side of said endless belt with said
feed chute extending in the direction of the platen and terminating
at the end of said housing adjacent said platen, upstream of said
print head, whereby cut forms record media may be fed alternately
through said at least one feed chute to the continuous forms record
medium, onto the periphery of the rotatable platen for imprinting
thereon by said print head.
2. The continuous forms feed tractor as claimed in claim 1, wherein
said at least one feed chute comprises a long cut forms feed chute
within said housing extending the length of the housing, parallel
to the top and bottom surfaces and opening outwardly at the rear
end of the housing to facilitate insertion of long cut forms
therein.
3. The continuous forms feed tractor as claimed in claim 1, wherein
said at least one feed chute within said housing comprises a
diagonal short cut forms chute within said elongated housing from
the top surface towards said bottom surface in the direction of
said platen and having a lower end opening at the front end of said
elongated housing adjacent said platen, and wherein said diagonal
short cut forms chute is laterally to the side of said endless
belt.
4. The continuous forms feed tractor as claimed in claim 2, wherein
said at least one feed chute further comprises a diagonal short cut
forms chute formed within said elongated housing from said top
surface towards said bottom surface and having a lower end opening
to the front end of said elongated housing adjacent said platen,
and wherein said diagonal short cut forms chute is laterally to one
side of said endless belt.
5. The continuous forms feed tractor as claimed in claim 3, further
comprising a spring biased, pivotable door mounted to said housing
along the side of said housing remote from said diagonal short cut
forms chute and to the opposite side of said endless belt from said
short cut forms chute, and wherein, said door is of a lateral width
such that a portion of the door overlies the entrance of the
diagonal short cut forms chute when in closed position, requiring
pivoting of the door to a substantially upright, open position to
permit insertion of short cut forms within said diagonal short cut
forms chute.
6. The continuous forms feed tractor as claimed in claim 3 wherein
said housing comprises an elongated, hollow, rectangular box-type
structure comprising spaced top and bottom walls, opposite end
walls joining said top and bottom walls, a side wall integral with
said top and bottom walls and said end walls, spanning between said
walls and extending below the bottom wall, and having integrally
formed therewith, at right angles thereto, an integral long cut
forms rear chute wall, said long cut forms rear chute wall being
parallel to the bottom wall but spaced slightly therefrom to
partially define said long cut forms chute, and wherein, the
box-type structure further includes co-planar, upper and lower,
integral inclined walls opening to the top surface of the top wall
and extending diagonally downwardly from the top wall in the
direction of the bottom wall and opening to the front end of the
housing adjacent said rotable platen, and defining said short cut
forms chute.
7. The continuous forms feed tractor as claimed in claim 6, wherein
said lower inclined wall extends beyond the end wall proximate to
said rotatable platen to ensure engagement between the short cut
forms record media and said platen upstream of said print head.
8. The continuous forms feed tractor as claimed in claim 6, wherein
the side wall of said housing, remote from the rotatable platen,
extends longitudinally beyond the end wall of said housing at that
end, and wherein, said long cut forms rear chute wall extends
longitudinally beyond that end wall of said housing to a similar
extent and is integral therewith to define a long cut forms chute
insertion mouth to facilitate insertion and feed of long cut forms
record media through said chute to the print area defined by the
platen and print head.
Description
FIELD OF THE INVENTION
This invention relates to a continuous forms feed tractor, and more
particularly to such forms feed tractor having the capability of
facilitating the feed of continuous forms having edge perforations;
long forms such as letter-size or legal-size sheets, and short
forms such as punch cards, through a printer for printing upon such
record media.
BACKGROUND OF THE INVENTION
Forms feed mechanisms function to synchronize movement of a paper
sheet, web or the like, through a printer. A pair of laterally
spaced, shiftable forms feed tractors are mounted on the forms
handling section of a printer so that they can be set in positions
determined by the lateral width of the forms being fed, and
function to facilitate the movement of paper past a print head. The
pair of tractors comprise elongated molded plastic or metal
housings, through which projects by way of suitable bushings, a
support shaft which extends laterally across the printer. The
tractors employ a releasable friction clamp for locking the left
and right tractors at laterally spaced positions on the support
shaft to define the path of the print medium form being fed through
the printer. Further, conventionally, an endless belt is mounted on
each of the housings, to its lateral outside within an appropriate
track. The endless belt, is provided with semicircular bars on its
inner periphery which are received within the valleys between
sprocket teeth of a sprocket, mounted for rotation at one end of
the elongated housing within the elongated housing, about which the
endless belt is engaged. A drive shaft, projects laterally across
the printer, through the sprockets and engages both sprockets to
drive the endless belts for the left and right tractors
respectively from a common drive motor coupled to the drive shaft.
Pins projecting outwardly from the endless belt at right angles to
the outer surface of the belt enter pre-punched holes on the
endless form record media along both sides thereof, and as the pins
move, they carry the paper forwardly through the printer.
U.S. Pat. No. 4,226,353, issued Oct. 7, 1980, to Silvio U.
Blaskovic et al, and assigned to the common assignee, shows a
continuous forms feed tractor of this type. Typically, the front
end of the elongated housing (relative to the feed path of the
endless forms record media) is in juxtaposition to a rotating,
cylindrical platen. The continuous forms record medium contacts the
periphery of the platen for rotation therewith, past a confronting
print head just upstream of the point where the perforations of the
endless forms record media engage the endless belt pins of the
forms feed tractors.
To maintain engagement between the continuous forms record medium
and the paired endless belts carried respectively by the left and
right tractors, each of the tractors have mounted thereto, to the
lateral outward side of the endless belt, a door which pivots from
a generally upright, forms access position, to a door closed
position where the door overlies the endless belt, and functions to
sandwich the endless forms record medium, in the area of the
perforations, against the top of the elongated housing of the forms
feed tractors.
In U.S. Pat. No. 4,226,353, the door is pivotally mounted by means
of pivot pins fixed to the door at respective ends and pivotally
mounted within snap fit slots of flanged receivers projecting
outwardly and upwardly of the elongated housing. Additionally, one
or more coil springs are connected between the elongated housing
and the pivotable door, at a point above the pivot axis defined by
the pins carried by the door. Further, stops are formed on the
flanged receivers for ensuring that when the doors are open, they
rotate such that the springs pass through the centers of rotation
of the door pivot mounting pins, thereby ensuring that the doors
are maintained in their upright or raised position under an
overcenter action to prevent inadvertent closure.
Such continuous forms feed tractors have operated adequately in
feeding continuous forms record media through wire or other type
printers, however, there is a current need for such printers to
randomly print on other than such continuous forms utilizing edge
perforations as positive drive feed of the forms through the
printer. Attempts have been made to facilitate the feeding of
record media such as letter-size or legal-size paper sheets through
the printer. IBM Technical Disclosure Bulletin, Volume 23, No. 7B,
of December, 1980 to M. F. Davis, Jr. et al shows a cut-forms guide
in the form of a chute 10 mounted to a horizontal front pivot rod
of a forms wire rack assembly. This permits the chute to be
adjusted to and fixed at an appropriate print position with the
left edge of the guide becoming the left side of the paper, thereby
assuring consistent forms feed into the pressure roll assembly when
loading forms.
In at least one IBM Series/1 4974 commercial printer, a specially
formed, molded plastic cut form chute assembly is insertably
installed on positioning studs of the printer, after removal of the
continuous form tractor assembly, to facilitate the use of cut
forms type record media in lieu of the continuous forms type having
the perforated edges. While the cut forms chute as a installable
unit functions adequately to feed cut forms such as letter-size or
legal-size paper of predetermined width, the substitution and
replacement of the cut form chute for the continuous form tractor
assembly and vice versa is fairly complicated and requires a series
of steps to replace one for the other, to the inconvenience of the
operator of the printer.
It is therefore a primary object of the present invention to
provide an improved continuous forms feed tractor having the
capability of handling all of the present forms currently specified
for use in a standard continuous forms feed device, plus cut forms
such as IBM punch cards, legal-size and letter-size paper sheets
and the like without the necessity to add, subtract or substitute
components to the printer itself, and without compromising the
continuous forms feed mechanism of the printer.
SUMMARY OF THE INVENTION
In a continuous forms feed tractor for feeding a continuous form
record medium having edge perforations, through a printer about the
periphery of a rotatable cylindrical platen and in front of a print
head facing the platen for imprinting the record medium with the
continuous forms feed tractor being in juxtaposition to the platen
and wherein, said tractor comprises: an elongated housing,
including a top and bottom surfaces, a front end and a rear end,
said front end facing said platen and being juxtaposed thereto a
groove within the top surface of said elongated housing, an endless
belt born by said groove, a sprocket rotatably mounted in said
housing and engaging said belt for driving said belt, means for
rotating said sprocket, a door pivotably mounted to the side of
said housing for movement between a first, generally upright, open
position exposing said endless belt, and a second, face engaging
position with said continuous forms record medium and said housing,
pins projecting outwardly of the face of said endless belt and
engaging corresponding perforations along the edge of said
continuous forms record medium. The improvement comprises at least
one feed chute within said housing, having at least a portion
extending to the side of said endless belt and extending
longitudinally in the direction of said platen. Said at least one
feed chute terminates at the end of the platen, upstream of said
print head, whereby, cut forms may be fed alternatively to the
continuous forms, through said narrow slot onto the periphery of
the rotatable platen for imprinting thereon by said print head.
The continuous forms feed tractor may have an elongated long cut
forms feed chute extending the length of the housing, parallel to
the top and bottom surfaces and opening outwardly at the rear end
of the elongated housing to permit ready insertion of the long cut
forms therein. A diagonal slot may be formed within said elongated
housing defining a short cut forms chute from said top surface of
said elongated housing towards said bottom surface, opening through
the front end of said elongated housing adjacent to said platen
with said diagonal slot being laterally inside of said endless
belt. The pivotable door may be of a lateral width such that a
portion of the door overlies the entrance to the diagonal slot
requiring the pivoting of the door to the first open position to
permit short cut form access to the slot for feeding of punch cards
or the like. Both the short cut form and long cut form chutes may
be integrally molded into the elongated housing of the continuous
forms feed tractor, such that the short cut forms chute and the
long cut forms chute intersect each other upstream of the platen,
and to the side of the platen opposite the print head.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a medium speed wire printer
utilizing a pair of improved continuous forms feed tractors with
multiple cut forms chutes forming a preferred embodiment of the
present invention.
FIG. 2 is side elevational view of a portion of the printer of FIG.
1, illustrating one of the improved continuous forms feed tractors
with the basic printing components in juxtaposition thereto.
FIG. 3 is a top plan view partially broken away, of the improved
continuous forms feed tractor illustrated in FIG. 2.
FIG. 4 is a side elevational view opposite to that of FIG. 2, with
door pivoted to record medium access position to allow short cut
forms to be fed to the print head.
FIG. 5 is a sectional view of the continuous form feed tractor of
FIG. 3 taken about line 5--5.
FIG. 6 is a sectional view of the continuous form feed tractor of
FIG. 3, taken about line 6--6, showing the clamp for selectively
clamping the tractor to its support shaft.
FIG. 7 is an exploded view of the clamp illustrated in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a medium speed wire type printer is indicated
generally at 10, sized for desk top mounting, and is comprised of a
base 12, to which is removably mounted, a top cover 14. Base 12 and
cover 14 form an essentially rectangular, parallelpiped housing 16
for housing the printer components within the interior of the base
12 and cover 14. Detachably mounted to the rear of top cover 14,
and projecting upwardly therefrom, is a continuous form tractor
assembly, indicated generally at 18. It is within the continuous
forms tractor assembly 18 that the invention resides, particularly
with respect to two continuous forms tractors, i.e., a left
tractor, indicated generally at 20, and a right tractor, indicated
generally at 22. Extending laterally across the tractor assembly 18
are a pair of rods comprising a support shaft 24, of circular
cross-section, and a square cross-section continuous forms tractor
drive shaft 26. Alternatively, the shaft 26 could have a hexagonal
cross-section or be splined. Slidably mounted on the support shaft
24 are left tractor 20 and right tractor 22, which tractors may be
selectively shifted in position on the support shaft 24 and
frictionally clamped thereto, at laterally adjusted positions. As
such, the machine may imprint continuous forms record media of
various widths. This is accomplished as in the description of the
prior art by the media having edge perforations on one or both
edges for feeding through the machine. As illustrated in FIG. 1, to
the rear of shafts 24 and 26 are a plurality of continuous forms
rollers, as at 28, mounted for rotation about their axes on roller
support shaft 30. Additionally, a specially formed wire rack 32 is
fixedly mounted to the tractor assembly 18 at opposite ends so as
to overlie the rollers 28 and it functions to guide, due to its
curvature, the movement of the continuous forms record media
leaving the left and right tractors 20, 22, to the rear of the
printer 10. As may be appreciated, paired generally inverted
L-shaped side arms 34 are mounted to the top cover 14 of the
printer and support the left and right tractors 20 and 22, the
continuous forms rollers 28 and wire rack 32.
Referring next to FIG. 2, there is shown in somewhat schematic
form, the principal components of the printer 10 including the left
tractor 20, which is shown in side elevational form. In that
respect, within the printer 10, some of the components are mounted
within base 12, and the others within top cover 14. The principal
components of the printer comprise a print head indicated generally
at 36, an elongated cylindrical platen indicated generally at 38,
and the left tractor 20. The left and right tractors comprise an
elongated, generally bar-shaped housing indicated generally at 40,
which may be formed of molded plastic, and with the exception of
the present invention, functions primarily to support for endless
movement, an endless belt 42. In conjunction with that function, as
a second component of each tractor, there is provided a pivotal
door indicated generally at 44 in the manner of prior U.S. Pat. No.
4,226,353.
The details of the forms feed tractors 20, 22 may be readily had by
reference to U.S. Pat. No. 4,226,353, and the description herein is
limited to the components related to the general use and function
of the tractors 20, 22 including the cut forms feed mechanism.
Housing 40 is comprised of two sections 74, 76 which are laterally
side-by-side joined in the manner of U.S. Pat. No. 4,226,353.
Housing 40 is provided with a top surface 46, a bottom surface 48,
a front end 50, and a rear or back end 52. It may be of molded
plastic form and has laterally spaced side walls at 54, 56. Side
wall 54 is the outside side wall of housing 40 within section 74
and side wall 56 is inside thereof as part of section 76, facing
tractor 22. Tractor 22 is identically formed, as a mirror image, of
tractor 20.
In accordance with U.S. Pat. No. 4,226,353, the side walls 54, 56
are provided with the appropriate bushings as at 58, 60, bearing
holes as at 62 and 64 respectively. Mounted within the holes 62, 64
and sandwiched between outer side wall 54 and inner side wall 56 is
sprocket 21, having a square cross-sectional bore through which
extends drive shaft 26, configured and sized thereto, such that
drive shaft 26 drives sprocket 21. The sprocket 21 is mounted
internally of the housing 40, that is between side wall 54 and side
wall 56. Additionally, inner housing section 76 is formed with an
elongated D-shaped projection 66, FIG. 5, to form a track 78 within
housing 40 sized to endless belt 42. Belt 42 mounts to the housing
40 by separating lateral sections 74, 76 of the housing 40, with
the belt being slipped onto a pre-formed track 78 and about
sprocket 21. Structurally, this is identical to U.S. Pat. No.
4,226,353.
The sprocket 21, which is of cylindrical or disc form, includes a
plurality of sprocket teeth 68 on the periphery forming
semi-circular grooves or valleys 67 between the teeth. The endless
belt 42 includes a plurality of transversely extending bars 82a of
corresponding semi-circular cross-section spaced along the bottom
of the belt which may in fact be integral extensions of pins 82,
projecting outwardly of the endless belt 42. As such, the endless
belt is driven by a drive shaft 26. Further, the endless belt 42,
which may be a strip of non-stretchable polyimide film such as
Kapton, is sized laterally, slightly narrower than the width of the
track 78 bearing the same, so that, the projecting pins 82 project
through perforations of corresponding size within the continuous
forms record medium 84 to drive the continuous forms record medium
84 through the printer over and across the continuous forms rollers
28, after leaving left and right tractors 20, 22, in the manner of
U.S. Pat. No. 4,226,353.
In FIG. 2, it may be seen that the continuous forms record medium
84 is supplied from a source (not shown) as evidenced by arrow 86,
such that the continuous forms record medium 84 pass over a
horizontal alignment rod 88, between enlarged flanges or ends as
90. The continuous forms record medium 84 moves into contact with
the periphery 92 of platen 38, and is pulled around the platen by
the fact that the holes in the edge perforations are engaged in the
tractor drive pins 82. A plurality of sets of axially spaced
pressure feed rolls 94, 96, rotatable about their axes on roller
shafts 95, 97, respectively, extend laterally parallel to the
bottom of the platen 38, and are pressed against the platen 38 by
means such as springs under compression forces, as indicated
schematically by arrows 98, such that the peripheries of pressure
feed rolls press against the lower side of the cut forms during
conditions in which a cut form is fed through the printer 10. A
curved paper deflector indicated generally at 100, extends beneath
platen 38, and is fixed within base 12. The paper deflector 100 has
two sets of cut-outs or windows, at at 102 and 104, located
intermittently along the length of the same through which, the
pressure rolls 94, 96 pass under applied pressure 98. When
continuous forms 84 record medium is being fed through the printer,
then the pressure feed rolls 94, 96 are disengaged and moved
downwardly and away from the periphery 92 of platen 38 by means
(not shown). The platen 38 may be mounted for rotation about its
axis by way of platen support shaft 106 which shaft 106 is mounted
for rotation upon base 12, with the shaft ends projecting through
and beyond the ends of cover 14. Typically, platen knobs as at 108,
FIG. 1, are fixed to the platen support shaft 106 at opposed ends
to permit the platen to be manually rotated, as desired.
The print head 36 is being shown mounted within base 12, physically
oriented in a horizontal position having end 36a facing the side of
platen 38. The print head bears a plurality of print wires in a
matrix fashion, as indicated at 110, for selected wire projection
towards and away from any of the record media passing across the
end face 36a of the same, borne by the rotating platen 38, i.e.,
such as a continuous forms record medium 84.
To permit laterally sliding movement of the left and right tractors
20, 22 towards and away from each other for adjusting the lateral
gap therebetween to accommodate to the width of the continuous
forms record medium, or in the case of the instant invention, to
adapt the left and right tractors to the lateral width of either
short or long cut forms to be fed through the printer 10, each of
the tractors 20, 22 include a pivotable clamp indicated generally
at 112, mounted to the outer and inner side walls 54, 56 of the
elongated housing 40, and which slidably receives the support shaft
24 of circular cross-section. Clamp 112 consists of inner sleeve
114 concentrically surrounding shaft 24, which in turn
concentrically supports outer sleeve 116. Unlike U.S. Pat. No.
4,226,353, in which the clutch or clamp 60 comprises a threaded
adjusting screw to draw a lower arm upwardly towards an upper arm,
thereby reducing the diameter of the hole internally and to clamp
about the rotary shaft projecting therethrough, the clamp 112 of
the present invention has outer rotatable sleeve 116 carrying
integral, radially projecting double actuating handles 118a and 118
b.
Outer sleeve 116 includes four flats or cams 116a in
circumferentially spaced positions within the inner periphery of
the outer sleeve 116. Inner sleeve 114 includes four edge flanged
flexible fingers 120 defined by a pair of right angle slots 121
extending partially over the length of the inner sleeve from its
tip end 114a inwardly. Further, the tip ends include slight
radially enlarged flanges 114b which abut the ends of the flats or
cams 116a of the outer sleeve 116. The inner sleeve 114, at its
end, includes a radially enlarged flange 122 having flats 122a on
diametrically opposed sides, and is further provided with a
radially projecting arm or stop 124 integral therewith.
Within the inside side wall 56 of the housing inner section 76, on
the side remote from housing outer section 74, there is provided a
recess 126 which is configured to and slightly over-sized relative
to flange 122 of the inner sleeve 114, and which includes a
radially projecting recess portion 126a, which receives the
radially projecting stop 124 of flange 122. As such, the inner
sleeve 114 is inserted within a hole 128 of D-shaped projection 66,
FIG. 5, and arm 124 is loosely received within recess portions
126a. The inner sleeve has a circular bore 130, FIG. 4, through
which the support shaft 24 passes. By rotation of the handle 118 of
the outer sleeve 116, approximately 45.degree., the cams or flats
116a move into contact with the rounded outer peripheries of the
fingers 120 to compress the fingers tightly against the shaft 24,
and thus, securely frictionally lock the tractors 20, 22 at given
longitudinal positions on the support shaft 24.
To the side of sleeve 116, opposite handles 118a and 118b and
projecting radially outwardly therefrom, diametrically to double
handles 118a and 118b, is a pin 119, and projecting longitudinally
outwardly of side wall 54 of housing 40 are a pair of stops 132,
circumferentially spaced approximately 45.degree.. The double
handle allows for a push lock and push unlock operation of the
clamp. The stops 132 limit rotation of the outer sleeve 116 between
positions where the clamp 110 is engaged and disengaged with shaft
24. This functions to frictionally lock the left and right
tractors, 20, 22, at selectable positions along the length of
support shaft 24.
Pivotable door 44 is pivotally mounted to elongated housing 40 and
spring biased much in the manner of U.S. Pat. No. 4,226,353. In
that respect, the housing outer section side wall 54, is provided
at opposite ends with integral flanged pin receivers 134, which in
the case of this embodiment, are identical, and have upwardly
facing snap fit arcuate slots 136, FIG. 3. The slots 136 form pivot
mounts for unitary pivot pins 138 of the door 44, which pins 138
project outwardly at opposite ends 140 and 142 of door 44. The pins
138 are spaced from the lower edge 144 of the door 44, so as to
permit the door to pivot relative to pin receivers 134.
Additionally, adjacent to each receiver 134 is a vertical stop 146
at each end of the housing section 74 integral with the flanged
receiver 134. The stops 146, at their upper ends, contact legs 148,
which depend from the lower edge 144 of door 44 and integrally
carry the laterally extending pivot pins 138 for door 44. At the
center of upper edge 140 of door 44, there exists an inclined lift
tab 142 which permits manual pivoting and lifting of the door 44
from its generally horizontal position to a door open, beyond
vertical, position. Further, integrally formed and projecting
outwardly of outer side wall 54 of the housing 40 for each of the
tractors 20, 22, is a coil spring mount 146 of L-shaped form
terminating in a tapered, headed pin 150, about which, one end 152a
of a coil tension spring 152 engages, the coil spring end being
held on the pin 150 by its headed end 150a. In like fashion, the
door 44 includes a central cut-out or recess 154 within lower edge
144, and projecting laterally within the recess from opposite ends
are similarly tapered, headed pins, as at 156, about one of which
is wrapped the other end 152b of the tension coil spring 152. Two
coil springs 152 may be employed, if desired. The locations of the
L-shaped spring mount 146 and the headed pin 156 on door 44 are
such that, during pivoting of the door 44 from either open position
to closed position, or vice versa, the spring 152 crosses over and
through the pivot axis for the door as defined by pivot pins 138,
thus these elements function as an over center spring mechanism 158
for maintaining the door 44 in closed position when closed, or in
open position when open, and causing legs 148 of the door, to
contact stops 146 when in door-raised and door-open position.
In accordance with the prior U.S. Pat. No. 4,226,353, the door is
provided with an elongated groove 160 on its lower face 44a opening
to a pair of slots, as at 161, which slots extend through the door.
Endless belt pins 82 pass through the perforations at the edges of
the continuous forms record medium 84 and are received within
groove 160 to carry the continuous forms record medium 84 across
the top surface 46 of the elongated housing 40 for each of the
tractors 20, 22, sandwiched between the door and that housing
surface.
The present invention is directed to the modification of the
elongated housing 40 of each tractor 20, 22, so as to accommodate
and facilitate the feed of both relatively long cut forms, such as
letter-size or legal-size stationary paper sheets, and short cut
forms such as punch cards or the like. Inner housing section 76 is
molded or otherwise formed such that an elongated hollow
rectangular box type structure FIG. 2, is formed inwardly of side
wall 56 including end walls 162, 164 and flat top and bottom walls
166, 168, respectively. Side wall 56 extends below bottom wall 168
and supports at right angles thereto, an integral rear chute wall
170, parallel to bottom wall 168 but spaced slightly therefrom. In
that respect, side wall 56 of the inner housing section 76, flat
bottom wall 168 and rear chute wall 170 which extends parallel to
wall 168, form a long cut forms or rear chute 172 which is parallel
to the top surface 46 of elongated housing 40. Essentially, housing
section 76 is in the form of a rectangular box, having a planar
wall 170 underlying, but spaced slightly from the bottom wall 168
of that box.
In addition thereto, it should be noted that to the rear, side wall
56 of housing section 76 extends longitudinally beyond rear end 52
of the elongated housing 40, and rear chute wall 170 also extends
some distance beyond that of rear end 52. This forms a mouth which
facilitates the insertion and feed of the long cut forms into chute
172 and hence to the print area as defined by platen 38 and print
head 36.
In addition to the long cut forms chute 172, the inner section 76
of housing 40 is provided with a short cut forms chute indicated
generally at 174, which extends diagonally downwardly from the top
surface 46 of housing section 76 in the direction of the bottom
surface 48 of that member. Further, it opens to front end 50 of the
housing 40 of each tractor, and is formed by spaced, co-planar,
integral upper and lower inclined walls, as at 176, 178,
respectively. Inclined lower wall 178 terminates some distance
beyond the end 168a of bottom wall 168, the purpose of which is to
feed short cut forms record media, such as a punch card 180 into
the printing area as a further alternative to feeding the long cut
forms record media such as legal-size or letter-size stationary
sheets 182.
As may be appreciated, in addition, forward of short cut forms
chute 174, the top wall 166 of the housing inner section 76 also
inclines downwardly at 166a in the direction of the platen 38 to
facilitate the movement of continuous forms record media, after
printing, up and out of the area under engagement, at each side
thereof, by the pins 82 projecting outwardly of endless belts
42.
With respect to each of the tractors 20, 22 which are mirror images
of each other, there are some differences between the structure of
these tractors and the content of U.S. Pat. No. 4,226,353 other
than in terms of the incorporation of integral chutes for feeding
larger length cut forms record media 182, such as letter-size and
legal-size stationary, and much shorter cut forms record media 180
such as punch cards. While each of the housings 40 is formed of a
laterally outer section 74, screw mounted to a inner housing
section 76 by screws 184, FIG. 4, two differences exist, the first
in the clamping mechanism for effecting clamping of the tractor and
fixed at a laterally spaced position along support shaft 24, and
secondly, the nature in which the endless belt 42 is carried within
the housing 40 at the end opposite that bearing sprocket 66.
In U.S. Pat. No. 4,226,353, the section of the elongated housing
bearing the endless belt, incorporates a spring loaded tensioner,
in the shape of the letter D, which is spring biased so as to move
longitudinally towards and away from an integrally molded
projection on the side of that section, intermediate of the
tensioner and the sprocket, about which projection the endless belt
rides. The tensioner is eliminated in the left and right tractors
20, 22 of the present invention. Instead, the projection on the
face of the inner section 76 of the housing 40, is unitary and
fixed, and the element can be described as constituting a very
elongated D configuration, which is rigid and integral with the
molded section 76 itself. It functions therefore, as a purely
static guide for the endless belt 42, and performs no tensioning of
that belt. Adjacent to the vertical end face of projection 66 is
the sprocket 21, identical in configuration and mounting to that of
U.S. Pat. No. 4,226,353.
As may be appreciated in accordance with U.S. Pat. No. 4,226,353,
each of the parts described herein, with the exception of belt 24,
spring 26 and the screws 184, may be constructed of a molded
fiberglass reinforced polycarbonate. In operation, the continuous
forms record medium feeds in the manner of U.S. Pat. No. 4,226,353.
The pressure feed rolls 94, 96 are disengaged from platen 38.
Absent the feed and printing on that medium, the pressure feed
rolls 94, 96, are engaged, permitting the movement of either short
or long cut against the platen forms record media, as at 180, 182,
respectively, through chutes 174, 172, respectively, for movement
between feed rolls 94, 96, and the platen 38, and about the
periphery of the platen in a position facing print head 36 for
printing thereon, and then, outwardly therefrom, through a cut
forms output path, as indicated generally at 186, FIG. 2, which is
different from the continuous forms record medium output path, as
defined by housings 40 and door 44 of left and right tractors 20,
22, respectively.
While the invention is particularly shown and described with
reference to a preferred embodiment thereof, it will be understood
by those skilled in the art, that various changes and formal
details may be made therein, without departing from the spirit and
scope of the invention.
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